Propeller



oct. 2o; 1936. Q. {Asg'ALA A' g '2,058,122

PROBELLER f Filed Feb. 11, 1955v wir INVENTOR.

Patented Oct. 20, 1936 -Uiufrro STATES PATENT OFFICE PROPELLER Anthony Assala, Des Moines, Iowa Application February 11, 1935, Serial No. 5,925

This invention relates to propellers and more specifically to air propellers as used in the airplane art and may be considered as an improvement on the propeller disclosed in my issued "'1Patent No. 1,519,102, under date of December 16,

The VprincipalY object of my invention is to provide a-propeller that tends to eliminate the usual-slippagei at the outer end portions of Lthe bladeswhichas' is` well known, seriously reduces the efficiency ofthe propeller.

JA further object of this invention isto provide a highly eiiicient propeller for airplanes, dirigibles, and like that is not only of one-piece con- *"strl`iction, but one that has no mechanism or individual movingparts. I

A still further object of my invention is to provide a propeller construction that draws the air for like medium inwardly and rearwardly to ZU-and through the hub portion of the propeller, and then castsfthe same laterally back of the main radial blades of the propeller.

A still further object of my invention is to provide a propeller having both main radial wing blades and hub blade members that is so constructed that the hub blade members extend to positionsboth in advance and rear of the radial blades. i

A still further object of my invention is to 305 provide a combination hub and radially bladed propeller Athat is rened inappearanca'durable in use, .and economical in manufacture. v

These and" other objects will beV apparent to those skilled in the art."

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims .and illustrated in the 40- accompanying drawing, in which:

Fig. 1 is a front view of my'propeller designed to rotate counterclockwise ready for use.

Fig. 2 is a rear view of my `propeller and illustrates the fact that the back of the hub portion 4.5iv has no a'ir passageways extending through it.

Fig. 43 is a side View of the hub portion of my propeller.

Fig. 4 isa cross-sectional View of the hub portionv of my propeller, `taken on line 4-4 of 501`Fig.3.

` Fig. 5 isa side View of my propeller'with the radial blades c ut away and is taken at a right angle to that of the View shown in Fig. 3.

Although my propeller disclosed in my hereto- 55"u forer'eferred` to-issued patent was highly eflicient stt and desirable, it did have certain objections which have been overcome in my present propeller. I enumerate the objections as follows: Firstly, its hub portion was not properly streamlined; secondly, the hub blade elements did not continuously extend from front to the rear air exits in the hub portion; and thirdly, and most important of all, the airpassing through the hub portion was not cast out directly laterally and radially of the hub portion and to points directly back of the main wing blades. In other words, while my previous propeller had its rear end hub portion open, my new herein described propeller is completely closed.

The overcoming of these objections in my previous propeller by my present propeller will readily be hereinafter understood and which I will now describe: e v

Referring to the drawing, I have used the numeral I0 to generally designate the hub portion of my propeller. Extending from the periphery of this hub portion are the usual two oppositely disposed radial main Wing blades II and I2, as shown in Fig. 1. The relatively small centrally located hub blades herebefore referred to are in reality the mere construction of the hub IU in which are spiral passageways I4 and I5, which may beY considered With the hub shell as of turbine construction. This hub I U, which isof the nature of a turbine, is stream-lined by having its front bullet-shaped, as shown in Fig. 1V and Fig. 5. The back surface of the hub Yis flat and has no opening communicating withthe passageways I4 and I5. These passageways have their forward ends communicating with the outside atmosphere at diametrically opposite positions on each side of the central hub shaft attaching sleeve I3, respectively. These openings of these passage- Ways are each of elongated slot construction and extend from a point adjacent the center of the hub to a point near the root of the leading edge of the main radial blade adjacent to it, as shown in Fig. 1. As the plane of the leading edge of each of the blades cuts a line in advance of the center point of the hub these openings of the passageways, while being radially disposed, are, however, not longitudinally arranged as to the blades I I and I 2, but are disposed at angles thereto. These passageways I4 and I5 of the turbine constructed hub extend rearwardly and outwardly in oppositely arranged spiral paths, as shown by dotted lines in Fig. 2; the walls'of the passageways performing the function of the hub blades.V

Each passageway has its rear end communicating with the outside atmosphere near the back side of the hub in the form of an elongated slot, as shown in the drawing. Each of these outlet slot openings of the passageways I4 and I5 are comparatively long by extending substantially one-quarter around the rear side periphery of the hub. As the passageways I4 and I5 extend concentrically relative to each other and in opposite spiral directions radially through the hub portion, the passageway I4 will terminate under and in advance of the blade I2, while the passageway I5 which has its entrance adjacent the blade I2, will terminate under and in advance of the main blade II. As the slot exit openings of the passageways are in the periphery of the hub, any medium passing through and out of the passageways will be cast directly radially from the hub and back and under the main blades II and I2. This feature is very important for several reasons. If the passageways instead terminated so as to cast the medium directly to the rear and such a propeller were on the shaft of a motor the medium would not only be obstructed in its flow by the motor, but would have a tendency to back up, seriously interfering with the efficiency of the hub portion of the propeller and the passage of new medium through the hub. Furthermore, the air or medium passing through the hub portion would not be directed outwardly and at a right angle to its original ow back of the main blades and for the increasing of their eiiciency. Still further, the hub portion would take care of a'considerable amount of air directly in front of it, but would not do much in the aiding of the main blades in pulling the propeller through the medium. On the other hand, by having the exit openings of the passageways terminating around the rear portion of the periphery of the hub, such as shown in the drawing, the air passing throughthe hub will be dissipated radially and in the rear of the propeller and not be aifected by the motor or other parts positioned in the rear of the propeller.

Also, it will be noted that the passageways extending rearwardly and outwardly in spiral formation, will take advantage of the movement of the medium by centrifugal forces and by the time the medium passes from the exits of the passageways it will be directed outwardly at a right angle to its original direction of flow. This changing iof the direction of the flow of the medium rpassing through the hub will provide desired power to the propeller and will be in addition to that obtained by the main blades I I and I2. Of course, my hub construction takes care of the medium directly in front of the same, which, without my construction, would have to move to the side of the hub in order to pass the propeller. This movement of the medium to the side of the propeller hub aids in the undesirable slip of the main propeller blades as it starts the air or medium radially before the main blades reach it. This only provokes the outward movement of the medium at the time the same is engaged by the main propeller blades, due to the fact that the main propeller blades themselves tend to move the medium not only rearwardlyfbut outwardly by centrifugal forces. It is for this reason that the extreme tips of propeller blades are indeed very ineilicient. However, by my hub construction, the air is not only taken care of that is directly in front of the hub, but considerable `Wardly and rearwardly as in an ordinary type propeller. This inward and rearward movement of the air in front of my entire propeller for increasing the eficiency of the main blades II and I2 is accomplished by the walls of the passageways I4 and I5 extending at a greater pitch than that of the pitch of the main propeller blades. Also, I have provided integral cup ears I6 and I'I on the front of the hub portion and adjacent the two passageways I4 and I5, respectively, as shown in the drawing.

These ear cup portions, which may be considered as a mere continuation of the outer wall of each of the passageways have their leading edges resting in a plane in advance of the leading edges of the main propeller blades, as shown in Fig. 3. These cup portions I6 and I'I extend from near the portion I3 of the hub to the leading edge of the main blade adjacent to them and preferably to points just slightly beyond the plane of the periphery of the chief hub portion I0, as shown in Fig. 1.

One of the greatest advantages, however, of the air passing through the hub being cast laterally back of the main blades is the building up of a. more dense medium directly adjacent the rear sides of the main blades, thereby increasing the eiilciency of the main blades from this standpoint. Also, this medium which is cast at substantially a right angle to the movement of the air initially contacted by the main blades, gives more resistance to the rearward movement of the air contacted by the main blades, thereby further increasing the efficiency of the main blades. It therefore will readily be seen that I increase the eillciency of the main blades by affecting the air both in front of the main blades and in the rear of the main blades.

As the propeller rotates very rapidly it is desirable that the leading edge of the exit of each of the passageways be in advance of the leading edges of the main blades, respectively, in order that the radially cast medium will be directly back of each blade. The cup ears I6 and I'I contact the air in front of the hub in the same manner as blades and guide the medium into the passageways. The member I3 is to facilitate the connection of the propeller to a shaft, but if the complete propeller be of metal, merely a hole through vthe center of the hub portion may be provided for the reception of a shaft.

'Ihe walls of the passageways also terminate in the rear of the trailing edges of the main blades in order that the air therefrom will be cast properly back of the main blades.

Although I have described my invention as particularly adapted to the airplane or like industry, it may be used to equal advantage Wherever an eiiicient propeller is desired. Its efciency is substantially the samein any medium and may be used as a stationary positioned propeller or one that is desired to travel through a comparatively still medium such as that experienced by airplane propellers.

Some changes may be made in the construction and arrangement of my improved propeller withoutv departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structur-e or use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. In a propeller, a hub portion having a solid back and an opening extending into said back for the reception of a shaft, two blades extending from said hub portion, and two spiral passageways extending in opposite directions radially through said hub portion each having its forward end communicating with the front of said hub and its rearward end communicating with the peripheral side of said hub and in close proximity to the solid back portion oi said hub portion.

2. In a propeller, a hub portion, blades extending radially from said hub portion, and two spiral passageways extending through said hub portion in opposite directions radially from each other and terminating at points on the periphery of said hub portion.

3. In a propeller, a hub portion, blades extending from said hub portion, two spiral passageways extending through said hub portion, and cup ear portions on the front of said hub portion for guiding a medium into and through said passageways.

4. In a propeller, a hub portion, blades extending from said hub portion, and spiral passage- Ways extending in opposite directions radially through said hub portion each having its forward end communicating with the front of said hub portion and its rear end communicating with the periphery of said hub portion; the walls of said passageways extending beyond the leading edges of said blades.

5. In a. propeller, a hub portion, blades extending from said hub portion, and spiral passageways extending in opposite directions radially through said hub portion each having its forward end communicating with the front of said hub portion and its rear end communicating with the periphery of said hub portion; the walls of said passageways extending beyond the leading edges of said blades and rearwardly of the trailing edges of said blades.

ANTHONY ASSALA. 

